1 files changed, 64 insertions, 20 deletions

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 7fb008bc9e..fdcd1a8fdf 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -20,6 +20,7 @@
 #include "qemu/range.h"
 #include "qemu/error-report.h"
 #include "qemu/memfd.h"
+#include "qemu/log.h"
 #include "standard-headers/linux/vhost_types.h"
 #include "hw/virtio/virtio-bus.h"
 #include "hw/virtio/virtio-access.h"
@@ -106,6 +107,24 @@ static void vhost_dev_sync_region(struct vhost_dev *dev,
     }
 }
 
+static bool vhost_dev_has_iommu(struct vhost_dev *dev)
+{
+    VirtIODevice *vdev = dev->vdev;
+
+    /*
+     * For vhost, VIRTIO_F_IOMMU_PLATFORM means the backend support
+     * incremental memory mapping API via IOTLB API. For platform that
+     * does not have IOMMU, there's no need to enable this feature
+     * which may cause unnecessary IOTLB miss/update transactions.
+     */
+    if (vdev) {
+        return virtio_bus_device_iommu_enabled(vdev) &&
+            virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);
+    } else {
+        return false;
+    }
+}
+
 static int vhost_sync_dirty_bitmap(struct vhost_dev *dev,
                                    MemoryRegionSection *section,
                                    hwaddr first,
@@ -137,8 +156,51 @@ static int vhost_sync_dirty_bitmap(struct vhost_dev *dev,
             continue;
         }
 
-        vhost_dev_sync_region(dev, section, start_addr, end_addr, vq->used_phys,
-                              range_get_last(vq->used_phys, vq->used_size));
+        if (vhost_dev_has_iommu(dev)) {
+            IOMMUTLBEntry iotlb;
+            hwaddr used_phys = vq->used_phys, used_size = vq->used_size;
+            hwaddr phys, s, offset;
+
+            while (used_size) {
+                rcu_read_lock();
+                iotlb = address_space_get_iotlb_entry(dev->vdev->dma_as,
+                                                      used_phys,
+                                                      true,
+                                                      MEMTXATTRS_UNSPECIFIED);
+                rcu_read_unlock();
+
+                if (!iotlb.target_as) {
+                    qemu_log_mask(LOG_GUEST_ERROR, "translation "
+                                  "failure for used_iova %"PRIx64"\n",
+                                  used_phys);
+                    return -EINVAL;
+                }
+
+                offset = used_phys & iotlb.addr_mask;
+                phys = iotlb.translated_addr + offset;
+
+                /*
+                 * Distance from start of used ring until last byte of
+                 * IOMMU page.
+                 */
+                s = iotlb.addr_mask - offset;
+                /*
+                 * Size of used ring, or of the part of it until end
+                 * of IOMMU page. To avoid zero result, do the adding
+                 * outside of MIN().
+                 */
+                s = MIN(s, used_size - 1) + 1;
+
+                vhost_dev_sync_region(dev, section, start_addr, end_addr, phys,
+                                      range_get_last(phys, s));
+                used_size -= s;
+                used_phys += s;
+            }
+        } else {
+            vhost_dev_sync_region(dev, section, start_addr,
+                                  end_addr, vq->used_phys,
+                                  range_get_last(vq->used_phys, vq->used_size));
+        }
     }
     return 0;
 }
@@ -306,24 +368,6 @@ static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_t size)
     dev->log_size = size;
 }
 
-static bool vhost_dev_has_iommu(struct vhost_dev *dev)
-{
-    VirtIODevice *vdev = dev->vdev;
-
-    /*
-     * For vhost, VIRTIO_F_IOMMU_PLATFORM means the backend support
-     * incremental memory mapping API via IOTLB API. For platform that
-     * does not have IOMMU, there's no need to enable this feature
-     * which may cause unnecessary IOTLB miss/update transactions.
-     */
-    if (vdev) {
-        return virtio_bus_device_iommu_enabled(vdev) &&
-            virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);
-    } else {
-        return false;
-    }
-}
-
 static void *vhost_memory_map(struct vhost_dev *dev, hwaddr addr,
                               hwaddr *plen, bool is_write)
 {